Answer:
3x^2y\sqrt(y)
Step-by-step explanation:
(\sqrt() means square root
its the 2nd one
If you're going to use technology (Brainly) to solve this problem, you might find you get a quicker answer using the technology of your graphing calculator.
It is often convenient to cast the problem in the form f(θ) = 0. You can do that by adding 1 to both sides of the equation.

8/9 / 4/9
=(8/9)*(9/4) Multiply by second reciprocal
=(2/1)*(1/1) Cross reduce
=2 Multiply
4d=42-6
4d=36
d=36:4=9
.....................
Height of each floor = 5 meters
time to travel from the first floor to 68th floor = ?
Speed of elevator = 7.5m/s
While an elevator travels from 1st floor to 68th floor, we will multiply the height of floor with 67 to get the distance covered by the elevator form 1st floor to 68th floor, the height of 68th floor will not be counted in the distance because an elevator reaches the 68th floor not covered the height of that floor.
Distance = 5 x 67 = 335m
Now calculate the time by using the formula;
time = distance / speed
= 335m / 7.5m/s
= 44.667 seconds
Thus, an elevator will take 44.667 seconds to reach 68th floor.